The American Medical Association's (AMA's) Council on Ethical and Judicial Affairs' (CEJA's) new “Guidelines to Prevent the Malevolent Use of Biomedical Research” are both timely and appropriate. These guidelines are a product of the increasing realization of the “dual use” potential of life science discoveries. Although biomedical research usually aims at the development of new medicines, vaccines, diagnostics, and so on, the very same discoveries that could benefit humankind in these ways also often have implications for the development of biological weapons. The CEJA Guidelines draw attention to this fact and hold that physician–researchers have responsibilities regarding the uses to which their discoveries are put. Medical researchers should assess the likely social benefits and harms of their work and avoid projects where the latter outweigh the former. Knowledge and the advancement of science should not be the only aims of scientists; “commitment to public welfare and safety” are also essential. Toward the aim of preventing the malevolent use of research discoveries, the CEJA states that “regulatory oversight” of research (with an eye to potential harmful uses of potential discoveries), increased ethics education of physician researchers, and sometimes perhaps even censorship of research findings, are warranted.